stewart



R. T. STEWART.

FUEL SUPPLY SYSTEM FOR INTERNAL comsusnow ENGINES.

APPLICATION FILED DEC. 28.1915- 2 SHEETS-SHEET I.

"wanna 3. 3 a

Patented Dec. 6, 1921.

R. T. STEWART.

APPLICATION FILED DEC, 28,1915- aw 1 mw BN v HHH'H N mm I I 1. H

FUEL SUPPLY SYSTEM FOR INTERNAL COMBUSTION ENGINES.

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citizenfof the United States-,-

Rain nsrnwenr, or rrrrsnunen, PENNSYLVANIA.

rnnL-snrrrsr svs'rnrvr non rnrnienrin ooainusrron' ENGINES.

To all wrtomitmay concern: I

Be it known that I, Ran) T. STEWART, a esiding at Pittsburgh, .-iliegheny coun U Pennsylvania, have invented a new ano useful Fuel- Supply System for Internet Combustion lilngines, of which thefollowingis a full, clear, and exact description, reference being had to the accompanyingdrawmgs, forming part of this specification, in which:

Figures land 2 are sectional elevations,.

a system of this characterwl1ich is espe cially applicable to automobiles or other similar service, where the fueli'supply tank is located, either constantly, or at intervals, at a level below that of the carbureting chamber. 1 I p 7 A further object of my invention is to provide a. systemof this kind which is sim-= ple in its construction, having but fewparts; which is self controlled, and which will operate effectively under-the varying conditions of service. ,1 p

Referring first to that formofmy invention shownin Fig. 1, the numeralQ designates a supply tank, vented to the atmosphere at 3, and from which the fuel is drawn into a supplemental tank 4 at a higher level, through thepipe 5. The tank 4.11m a feed pipe 6 leading from its bottom portion into the float chamber? of the car bureter 8. 9 designates. the usual float fori controlling the inlet to said chamben 1O is a suction'pipe connecting the'upper'portion of the float chamber with the upper portion of the supplemental tank a, and

having a branch 11 communicating with the carbureting chamber 12 above the, fuel supply nozzle 13'. 1e designates the air in let and 15 a controlling-throttle therein.

16 is a float in the supplemental. tank car rying the needle valve 17 which controls the communication between the interior of said tank and the suction pipe 910 This float may, however, be made to controlthe fuel supply pipe in the manner shown in Fig. 2, hereinafter described. This valve A lication,fiiednetemter'es, 1915. Serial as. 69,005; r

float chamber.

in oneor 'the other of its arrangements, 1 is animportant feature,'since-it prevents any possibility of flooding'through'th p pe 10."

lt will. be apparent that the vacuum or section which exists in the carbureting I chamber-12, due to the action of the engine,

will becommunicated simultaneously to the supplemental tank 4: and tothe carbureter float chamber 47. When the extent of the .vacuum ,issuliicient to lift the fuel to the top of the supplemental tank,.the excessof fuel entering said tank over that delivered tothe carbureterwill become automatically stored in said tank, causing the level to rise therein-until'the float 17 acts to close the communication to the suction pipe 10. After this time'a constant fuellevel is main tained in the supplemental tank under norma]. conditions, ready for delivery to the carbureter at any time the vacuum becomes insuflicient to lift the"-fuel to the supplew .mentaltank For instance, an automobile,

having its main supplytankQ located. atthe rear, and equipped with this vacuum system, when, .ascending a steep hill with fully opened'carbureter, will be feeding its carbureterwith fuel drawn. directly from the storage supply; in the supplemental tank, until-{such time as the hill is surmounted.

The re-chargingof the supplemental tank Will then at once automaticallybegin; The.

system is thus rendered automatic for all operating conditions. The suction passages whlch lnterconnect the inter or'of the supplemental tank, the float chamber and the; carbureting chamber, in addition to functioning in the manner above described, also provide a perfect ventfor any fuel vapor or air which would otherwise collect in the supplemental. tank These vacuum connections maintain at all times equal PIGSSUIGSlH thechambers which they interconnect, thus nsuring *a perfect gravity feed of fuel'from the supplemental and in; the. carbureter' tank to the'float chamber under all condi-' tions. In the type of carbureter illustrated in Fig. 1, fuelflow from the float chamber to the carbureting chamber is caused by the aspirating action of the air flowing through theVenturi tube around the fuel nozzle 13 which is disposed in thereof. 1

It will be furthernoted that the pipes 5, 6 and 10 are normally unrestricted,fno valves being required for the supplemental a restricted portion nozzle 13 chamber'except the valve operatedby the float l6, and which may control e1ther the pipe 10or the pipe 5.

F 1g- 2 shows another embodiment of invention which iseirceedingly flexible in its action and gives excellent results when ap plied to automobile service. The general construction and arrangement is the same asthatuescribed in Fig. l, and similar reference numerals have been applied to corrospending parts, with the letter a affixed thereto. 1 have, however, shown the lo-at 16 as having its valve 1? controlling the discharge of the pipe 5 in this forar. l have also shown a suplementaneedle control valve 18 interposed in the Euel'passage 19 leading from the float chamber to the carbureting chamber. 1 have also shown the latter as having a' hollow sl eve air valve.

' tocmploy. an anterior throttle valve 15 in with respect to the valve it the air inlet let, and aposterior throttle valve 26 in the connection leading from the carbureting chamber to the engine. Each'ot these valves is actuated by a crank 2'7, and the two cranks are connected bya twopart link 28, having a turnbuckle, or other adjustable connection 29.

By reason of the connection 28 the two throttles are actuated simultaneously, and by suitably adjusting the length of the link 28, or by shifting either crans: 27 angularly actuates, either throttle may be given a lead of opening over that of the other. In this manner de sired degree or" vacuum range may be had in the carbureting chamber. I

This series throttling arrangement possesses the advantages, without the attendant disadvantages, of a single throttle, whether the latter'be located at the inlet or the outlet. This is because the series throttles can be adjusted to give just the range of vacuum desired to lift the fuel to the top. of the supplementaltank. whereas. if the throttle 15 were used alone, it of necessity would give a vacuum range at least five times as great as is desired, with the at tendant operating disturbances. Furthermore, the series throttles can be made to operatewith a relatively small vacuum in the engine intake when the automobile is ascend mg asteep hill, with wide open throttles,

.rarified charge, which lessens the power veloped at timewhen maximum power is most desired.

The embodiment of my invention shown in Fig. 2 also furnishes a means for enriching the mixture when the engine speed is being accelerated. This desirable result is due to the unrestricted passages 6, l a and 11 (when open) in combination with the throttle 15 and the cushioned air valve. By more or less rapid opening of the throttle l5 or series throttles 15 and 26, an increase in pressurediiierence betweenthe air inlet chamber 30 and the carbureting chamber will temporarily occur. The amount and duration of this will depend, first, upon the rapidity'wi-th which the throttles are opened; second, upon the inertia of the air valve, and, third, upon the etlectiveness of the air valve cushioning. Because of the une striated passage 11 connecting the chamber 30 with the float chamber, there will be an increase in pressure difference between the float chamber and the carbureting chamber 12. This results in atemporary enrich ment of the mixture delivered tothe engine, and makes it possible to get the'automobile promptly under way after being "slowed down, as at crossings, etc., without being obliged to use an unnecessarily enriched mixture for ordinary operating conditions. The latter isnot only. uneconomical in the use of fuel, but" is aptto, toul the engine by excessive deposits of carbon.

This same means also provides for the ordinary running conditions, and is an aid to the aspirating action of the air; flowing in around the fuel nozzle. flow is substantially constant in action, while the aspirating action necessarily diminishes as the throttles approach their closed positions. When properly adjusted therefore, there is insured a pertectlysatistactory mixture for the widest possible range of both speed and-power conditions.

This means, or other equivalent device for automatically establishin in a definite manner higher pressure in the float chamber of a carburetor than that which simultaneously exists in its carbureting chamber, may be used, when properly proportioned, as the chief or only means for causing fuel tl w from the float chamber to the arbureting chamber, as, torinstance, in the application of my improved vacuum feed system, where This aid to fuel it is desired to use a non-aspirating type of carbureter.

Figs-3' and 4: show a practical structural embodiment of my vacuum fuel feed system,

it will be's'een that in this on i 1:.

in which the supplemental fuel storage chain: ber 1s made a part ofthecarbureter itself" In order to enable the construction more easily understood 1 ha e applied c responding reference characters to me inthese figures which correspond a; i

arts shown in Fin. 1.. with the lette o 3 emental ran my invention the su pen the carbur superimposed directly u and surrounds the airinlet- 1.4:", thefcarbu flOll.

reting chamber 129,1and the passag 3}. the carbureting chamber to the engine.

connection 10* corresponding to tbepipeif),

of Fig. 1, leads directly up through the fuel chamber of the supplemental t'anlz' l and terminates at its upper end in aremovable cap 82 which has an air space'commum'cat mg with the airspace 33 at thet'opof said This construction alsoj'permits the ante rior and posterior throttles and 26 tobe carried on a single common shaft 36, the two throttles being set at different angles with respect to the axis of said shaft so to give the throttle l5 a lead over the throttle 26",

' as more clearly indicated in Fig.3.

CII

This embodiment of my invention possesses the following further desirable characteristics; viz., it is simple and inexpensive,

to construct, and may be easily and readily attached to the engine by means of the bolting flange extension 37. It maybe given a rectangular or block form, and when attached directly to the engine body, it harmonizes perfectly with the block type of automobile engine now in vogue. Where the carburetor used with an air heater which. can be connected and disconnectedat will,

the range in temperature between summer and wmter conditions of the fuel supply can be greatly lessened, because of the fact that the supplemental fuel storage space immediately surrounds the air intake of the carbureting chamber.

I do not desire to limit myself to the embodiments of my invention which I have herein'shown and described. For example, various types of carburetors maybe substituted for those illustrated, provided that the parts are suitably proportioned, and means are provided for maintaining, at least periodically, under operating conditions, asufficient vacuum in the carbureting chamber, or other parts connected directly or indirectly thereto, to effect a fuel lift. Any suitable form of supplemental fuel tank may be used, and various other changes may be made within the spirit and scope of the appended claims.

mixture'outlet atjthe other end, a fuel" inner-e said carburetingpassageway,

float chamberflfeeding said fuelfinlet, aa throttle valve in said mixti'ire outlet, a sup- 7 plem'ental fuel-tank adapted to draw fuel from "a source "of supply, saidsupplemental tank being arrangediat a higher level than Q said float chamber to feed thereto, :suction means"communicating withs'aid carbureting passageway ata point anterior to saidthrottle' valveand extending tosaid float chamber andto said supplemental fuel tank, said suc'-- tion means beinw'operative; to create substantiallyequaldegrees of suction in said float chamber and sa d supplemental tank, and float controlled valve" in said, supplemental tank for "restricting the fuel leyel' therein.

2.- In combination, a'carbureting passageway having an air inlet and a mixture outlet, an aspirating fuel inlet to said carbu- "reting passageway, a float chamber feeding #1 said fuel inlet, a fthrottlevalve in said mixture outlet, a supplemental fuel tank ar ranged at a higher level than said float chain ber and'arranged toideliver thereto by gravi-ty throu'ghan interconnecting fuel passage, a suction passage communicating with said carbureting chamber at a point anterior to,

on i

said throttle valyefand extending to said float chamber abovethe fuel level therein, a

second valve anterior to said throttle valve;

and cooperating therewith for maintaining a predetermined range of suction between said valves, a suctlon passage communicating with said supplemental fuel tank above the fuel level therein and operative to create substantially equal 'degreesof suction in said i float chamber and in said supplemental fuel tank, a main fuelsupply tank, a fuel pas- 'sageway connecting said main supplytank with saidsupplemental fuel tank, and float controlled means in saidsupplemental fuel tank for restricting thefuel level therein.

3. Ina fuel supply system for internal combustion engines, thecombination with a carburetor, of asupplemental fuel supply. tank superimposed upon the carburetor, the

air intake of the carbureter, its carbureting chamber, and the passageway connecting said carbureting chamber with the engine intake extending through the. fuel storage space of the supplementaltank, substantially as described. i j

4:. Ina fuel supply system for internal combustion engines, the combination with a carbureter having the usual constant level chamber, of a supplemental fuel supply tank seated directly upon and over the carburetor,

said tank being of rectangular block form and having a bolting flange for direct attachment to the engine, substantially as described, the mixture outlet of said carbureter' extending out through the-side of said supplemental tank.

5. In a fuel supply system for internal combustion engines, the combination with a carbureter having a float chamber, of a supplemental fuel supply tank situated directly over the carbureter, an unrestricted passage connecting the fioat'chamber with the carbureting chamber, another unrestricted passageconnectin the float chamber with the upper portion of he supplemental tank, a main supply tank, a fuel pipe. connecting the two tanks, and: means for'automatically shutting off the feed/of fuel from the main nk to the supplemental tank when a given ,l is reached in the supplemental tank, substantially as described.

6. In combination, a carbureting chamber, having air and fuel inlets, a float chamber connected below tiiefuel level therein with said fuel inlet, a 'supplementaltank vplaced at a higl erlevel than and feeding liquid fuel to said float chamber, a main tank feeding liquid fuel to said supplemental tanka means for applying substantially the same degree of suction to said float chamber over ber having air and fuel inlets, a 'fioat chamber connected below) the fuel level therein with said fuel inlet a SU.) lemental tank placed at a higher level than and feed ing liquid fuel to said float chamber, a main tank feeding liquid fuel to said supplemental tank, means for applying suction through said float chamber over the fuel level therein and through said supplemental tank to the main tank, and a float controlled valve in said supplemental tank controlling the feeding of liquid fuel from said maintank to said supplemental tank.

In testimony whereof, I have hereunto set my hand.

REID T. STEYVART. l/Vitnesses Gno. B. BLEMING, GEO. H. PARMELEE. 

